Thread runoff device for double twist spindles



Jan. 11, 1955 LANDQLT 2,699,032

THREAD RUN OFF DEVICE FOR DOUBLE TWIST SF'INDLES F iled Aug. 11, 1950 2 Sheets-Sheet 1 mam IN VEN TOR.-

K. LANDOLT Jan. 11, 1955 THREAD RUNOFF DEVICE FOR DOUBLE TWIST SPINDLES Filed Aug. 11, 1950 2 Sheets-Sheet 2 INVENTOR.

United States Patent THREAD RUNOFF DEVICE FOR DOUBLE TWIST SPINDLES Karl Laudolt, Zurich, Switzerland Application August 11, 1950, Serial No. 178,852

Claims priority, application Switzerland August 12, 1949 11 Claims. (Cl. 5758.83)

The present invention relates to a thread guiding device for double twist spindles and is more particularly concerned with an improved thread guiding device which makes it possible to use imperfectly wound yarn bobbins.

Thread guiding devices formed by rotating plates or having a twisted wing-like form are known. These prior devices are not wholly suitable for use with imperfectly-wound yarn bobbins generally encountered in practice. In accordance with my invention, the shortcomings of the prior devices are avoided by the provision of thread guiding devices for double twisting spindles wherein the yarn bobbin is enclosed within a rotatable cage unit having a structure permitting the thread to pass from the bobbin to the exterior of the cage unit over substantially the entire height of the wound bobbin. The thread is led from the bobbin to a thread guiding member positioned outside of the cage.

The advantage of my thread guiding device as compared with thread guiding devices heretofore known, is that the thread can move up and down in a longitudinal direction in the cage unit so that it may be drawn from the yarn bobbin in the same direction as that in which it was wound. In accordance with my invention, it is possible to brake the cage and to make it of such dimensions that the tension on the thread remains constant.

Thus, I advantageously provide my thread guiding device with a brake means which, as the yarn speed becomes greater, automatically becomes weaker in action or ceases entirely, this operation being the result of the action of centrifugal force upon the brake means.

In the drawing, wherein are shown illustrative embodiments of the invention,

Fig. 1 is an elevational view of a double twist spindle arrangement embodying features of the invention and showing the rotating cage unit with a first and a second thread guiding member.

Fig. 2 is a sectional view of the embodiment shown in Fig. 1;

Fig. 3 is an elevational view of another embodiment of the invention;

Fig. 4 is a plan view, partly in section, of the embodiment of Fig. 3;

Fig. 5 is a vertical sectional view of the structure shown in Fig. 3;

Fig. 6 is a fragmentary plan view of a further embodiment of the invention;

Fig. 7 is a vertical sectional view of the embodiment shown in Fig. 6; and

Fig. 8 is a vertical sectional view of another embodiment of the invention.

Figs. 1 and 2 illustrate an embodiment of the invention and show how a simple construction of the rotating cage in accordance with the invention can be obtained by suitably shaping the thread-guiding members. The embodiment of Figs. 1 and 2 is characterized by simplicity of the thread-guiding arrangement and by improved accessibility. In this embodiment, the bobbin 101 is supported by the stationary tubular shaft 102 on which a stirrup 117 is supported above and below the bobbin 101. The first thread-guiding unit is formed by a downwardly bent member 118, the upper end of which is substantially vertical but which has a gradual 1y increasing slope as it bends downwardly. Depending upon the shape to which the wire member 118 is bent, it is possible to insure that the forces resulting from the thread tension are right angles to the thread-guiding 2,699,032 Patented Jan. 11, 1955 unit. From this it will be seen that the first threadguiding member follows the upward and downward movements of the thread windings on the bobbin and furthermore that the length of thread from the second thread-guiding member 119 over the first thread-guiding member 118 to the yard delivery bobbin remains constant, independently of the portion of the bobbin from which the thread is drawn. By suitably selecting the distance btween the first thread-guiding member 118 and the second thread-guiding member 119, it is possible to maintain a constant thread length and to maintain the resultant force at right angles to the first threadguiding member 118.

The second thread-guiding member 119 can be removably secured approximately at the height of the top edge of the delivery bobbin 101 and thus can lead the thread from the first thread-guiding member 118 directly to the center of the bobbin.

From Fig. 1 it will be seen that the angle of deflection of the thread on the rotating cage will vary, depending upon the portion of the bobbin from which it is drawn, i. e. from the top edge of the bobbin or from its bottom edge. The thread must also be lead over a stay in order to prevent it from touching the material on the bobbin when the bobbin is full. In operation, there is found to be a change of direction which is greatest when the thread is wound from the top edge of the bobbin and which is substantially nil when the thread comes from the lowest part of the bobbin. These differences in direction of the thread lead to a varying thread tension. In accordance with the invention, however, these tension variations can be nullified by providing the second thread-guiding member 119 with an extension 120a around which the thread must pass at an angle which increases with increase in distance from the guiding member 119 so that the total friction of the thread on all deflecting surfaces remains constant.

In order to prevent the formation of too large a thread balloon, there is advantageously provided a limiting ring 121 around the spindle. The ring 121 is suitably constructed from wire wound in the form of a spiral so that the threading-in of the thread is facilitated. Since the rotating cage, whether braked or not, generally brakes the thread sufficiently, it is not necessary to provide a special thread brake. This makes it possible in accordance with the invention to facilitate the threadingin operation to a considerable extent by providing a needle into which the thread can be set and threaded through the tubular shaft 102. The form of the needle is immaterial from the standpoint of the present invention and it may be an ordinary sewing needle, a wire with a bent or twist end, a clamp or the like.

In Figs. 3, 4, 5, 6, 7 and 8 are shown other embodiments of the invention. The common feature in the embodiments of Figs. 3 through 8 is that the cage, which is rotatable with respect to the bobbin, is supported only at one end, i. e. only at its upper end, by means of a central tube rotatable in a stationary vertical tube which serves as a bearing. This arrangement has the important advantages that the bobbin from which the thread is to be supplied is now readily accessible, since the guiding device can be completely removed by a simple manipulation. It is important that the entire cage and particularly its supporting shaft should be lightly constructed. The guiding device is always subject to vibrations which will have a reduced effect when the mass of the guiding device is small. In order to provide as light and rigid a cage as possible it has been found particularly advantageous to form the cage wall from a plurality of stays. Some of the stays preferably have a shield-like shape, and these stays together with straight stays, lie along a cylindrical surface.

The second thread-guiding member can then have the form of a twisted spiral and be fixed to the plate forming the cage end. It is of particular advantage to place the twisted spiral in such manner that the axis of its opening is tangent to the cylindrical surface of the cage. If the thread is unwound from the lower end of the bobbin, its deflection onto the shield-shaped stays is much less than its deflection when it is unwound from the upper end of the bobbin. On the other hand, however, the deflection of the thread upon engagement with the twisted spiral is greater when it is unwound from below, and there is thus obtained an equalization of the thread friction. As in the previously described embodiments, the cage is supported by a central tubular shaft. This shaft is itself 7 supported at two spaced bearing points whereby smooth rotation is insured. It is of particular advantage to support the thin walled tubular shaft at its lower end in a stationary tube which simultaneously serves as a bobbin carrier, the bobbin itself having the upper shaft bearing means in its upper portion. The bobbin is comparably heavy and therefore does not vibrate as much as do the other parts of the spindle. In all cases its vibrations are such that the shaft of the cage is held in two bearings with different vibrations which to a large extent compensate each other in their action on the shaft.

Referring more particularly to the embodiment shown in Figs. 3, 4 and 5, wherein corresponding parts are designated by the same reference numerals used in Figs. 1 and 2 with the addition of 100, the flanged bobbin rests upon a stationary tubular shaft 202 of the double twist spindle. The bobbin 201 is fixed into position by the ring 203. The actual guiding device consists of the stays 223 and 224, the plate 225, the central tube 226, the inlet eye 227 and the outer thread guiding member 228. As shown in Fig. 3, the stays are advantageously shield-like in form, i. e. substantially triangular.

By reason of the symmetrical construction of the stays 223 and 224. the guiding device can be used both for lefthand and right-hand wound bobbins and one of the bent stays 223 is employed as a first deflecting member While the oppositely lying twisted spiral 228 comprises the second deflecting member. The thread then passes over the inlet eve 227, throu h the central tube 226 and into the stationarv tube 202 f the double twist spi dle. If desired, the twisted spir l 228 and the inlet eye 227 may be replaced by rotat ble rollers. This may be done in order to reduce thr d friction.

Fi 3 il us r tes the two separate supporting units of t e thre duidin de ice formed by the two bushings 229 and 230 pressed into the tubular shaft 202. the bushing 230 serving simutaneously as a bearing. Since the guiding device mu t be light in weight a d also easily rotated, it will he u derstood that the tube 226 is not only thinw lled but h s as small a diameter as possible. For high thre d speed. it may also be advisable to balance the plate 225 by means of counterweights so that violent oscillations will be prevented even at high speeds.

In the embodiment shown in Figs. 6 and 7, wherein corresponding parts are designated by the same reference numerals used in Figs. 1 and 2 with the addition of 200, the thread-guiding device is supported in the tubular shaft 3 2 and in the bushing 332 which carries the ball bearing 331. The operation of the bearing remains the same whether the bobbin 361 has, as shown, a cylindrical bore or has a tapered bore. Thread-guiding means such as shown in Figs. 3 and 4 are also provided but have only been shown in part at 324.

Fig. 8 shows an embodiment of the invention which is suitable for bobbins having an extremely narrow bore. In this embodiment, wherein corresponding parts are designated by the same reference numerals used in Figs. 1 and 2 with the addition of 300, the tubular shaft 402 extends above the bobbin and the tube 426 is not only supported interiorly but is supported exteriorly on the tubular shaft 402 by the two bushings 433 and 434. The bushings 433 and 434 may be replaced by ball bearings. The stays 423 and 424 are advantageously formed from stainless steel wire or aluminum wire which may be heattreated or anodized. Tubes may be used instead of wire. The plates 425 are formed from wood or a plastic material such as phenol-formaldehyde resin, cellulose acetate, artificial horn or like plastic materials. The stays 423 and 424 may be cast in position or firmly secured by means of screws. The central tube is formed preferably from steel or aluminum while the bearing bushings are formed from fiber, artificial horn or other convenient material. Ball or roller bearings may be used. The eyes 228 in Figs. 3, 4 and 5 can be formed from wire or porcelain or the like, and the upper eye 227 is preferably formed from porcelain or the like and is preferably arranged so that it can be easily removed and replaced when necessary.

In the embodiment shown in Figs, 6 and 7, the cage is provided with a brake which is manually adjustable. In this brake the braking action diminishes under the action of centrifugal force. It has been found to be of particular advantage to make the brake shoe, which is pressed against an annular surface by means of a spring, to be sufficiently heavy that the braking force diminishes under the action of centrifugal force as the speed of rotation of the cage increases. By adjusting the tension of the spring it is possible to increase or decrease the action of the brake and by varying the weight of the brake shoe, either by making it smaller or larger or by selecting heavy or light materials, it is possible with increasing speeds of rotation to adjust the reduction of the braking force to safety the requirements in operation. It is possible to combine this adjustable brake with any other brake. For example, it is possible to actuate the brake in response to thread tension by providing a spring feelerlever which actuates the brake shoe through another spring. The spindle is suitable for a much greater range of thread speeds and thread thicknesses. This braking arrangement has the advantage that when the spindle is stopped, it prevents further rotation of the cage and thereby prevents breaking of the thread. In addition, it has the important advantage that it brakes the cage without permitting the spindle vibrations to be transmitted to the cage itself so that the cage, particularly if it is supported wholly or partly on ball bearings, is actually independent of the vibrations of the spindle. This is highly important since the resistance to rotation of the cage, which resistance has an important influence on the tension of the thread, thus becomes independent of the relatively strong vibrations of the spindle.

In the brake arrangement illustrated in Figs. 6 and 7, the brake lever 336 is carried on a portion of the plate 325, the lever 336 being pressed against the bushing 332 by means of the spring 337. It is possible to vary the force of the spring by inserting it in one or the other of the slots 338. The shape of the brake lever 336 and of the spring 337 are shown clearly in Fig. 7. Advantageously, the spring 337, which presses the brake shoe against the annular surface 332, also serves to hold the lever 336 on its support shaft 335. A further advantage of the construction shown is that the annular surface 332 against which the brake shoe 339 is pressed contains the upper bearing for the device. Advantageously the surface 332 also has a hub 340 on its lower side which can extend into the bobbin. To minimize vibrations, it is desirable to provide the annular surface 332 with a flexible disc 341 lying between it and the bobbin. With advantage, the plate 325 also has a projection 342 which limits the range of movement of the brake lever 336 so that it can rise only a limited distance from the braking surface 332, even at high speeds of rotation.

What I. claim is:

l. A thread guiding device for double twist spindles having a stationary tube adapted to carry a bobbin, said device comprising a cage rotatably supported on said stationary tube exteriorly of the bobbin, said cage being open to permit free passage of the thread from the bobbin to the outside of the cage over substantially the entire height of the bobbin, and a portion of said cage defining a first thread'guiding and deflecting surface engageable by the thread being unwound, said first thread-guiding and deflecting surface being substantially vertical at the upper portion of the cage and curving gradually to its lowermost end, the curve increasing in slope as it approaches said lowermost end, and means defining a second threadguiding and deflecting surface rotatable with said cage and positioned approximately at the level of the upper end of the bobbin, the thread from the bobbin being adapted to pass from the bobbin to the exterior of the cage over said first guiding surface and over said second guiding surface and then to pass through the said stationary tube.

2. A thread guiding device for double twist spindles as defined in claim 1, wherein the portion of said cage defining said first thread-guiding and deflecting surface is formed from a curved wire.

3. A thread guiding device for double twist spindles as defined in claim 1, wherein said first thread-guiding and deflecting surface is curved in such manner that the thread length from the bobbin to the second threadguiding and deflecting surface is constant.

4. A thread guiding device for double twist spindles as defined in claim 1, wherein the second thread-guiding and deflecting surface is provided with a curved portion which deflects the thread at an angle which is greater the lower the point at which the thread is removed from the bobbin and led over the first thread-guiding and deflecting surface.

5. A thread guiding device for double twist spindles as defined in claim 1, wherein the sides of said cage,

including the portion defining said first thread-guiding and deflecting surface, are formed from wire members arranged in cylindrical form, at least some of said members including the portion defining the first thread-guiding and geflecting surface being bent substantially into triangular orm.

6. A thread unwinding device for double twist spindles as defined in claim 1, wherein said cage is rotatably supported on said stationary tube only at the upper end of said cage.

7. A thread-guiding device for double-twist spindles having a stationary tube adapted to carry a stationary bobbin wound with thread and adapted to provide a passageway for the withdrawal of the thread, said device comprising a rotatable plate supported by antifriction bearings carried by one end of said stationary tube and said stationary bobbin, said rotatable plate carrying thread-guiding means exteriorly of said stationary bobbin for receiving the thread from said bobbin and guiding the thread in its passage from the bobbin to the interior of said tube, means defining a stationary braking surface, a brake shoe connected to said rotatable plate, and spring means normally urging said brake shoe against said braking surface, said brake shoe being adapted to be pivoted away from said braking surface against the action of said spring means under the influence of centrifugal force, whereby the braking action is reduced as the rotational speed of the plate increases.

8. A thread guiding device for double twist spindles as defined in claim 7, wherein said rotatable plate has a horizontally disposed circular portion above the bobbin, said brake shoe being mounted on a brake lever pivotally mounted on said circular portion on a vertical axis.

9. A thread guiding device for double twist spindles as defined in claim 7, wherein said plate is rotatably supported in a bearing bushing and said braking surface is provided on said bushing.

10. A thread guiding device for double twist spindles as defined in claim 9, wherein said bearing bushing includes a hub adapted to be supported by the bobbin.

11. A thread guiding device for double twist spindles as defined in claim 10, further comprising a resilient member disposed between said bearing bushing and the bobbin.

References Cited in the file of this patent UNITED STATES PATENTS 1,367,709 Noble Feb. 8, 1921 1,403,832 Beede Jan. 17, 1922 2,050,243 Bouget Aug. 11, 1936 2,390,454 Murphy Dec. 4, 1945 2,511,639 Koella June 13, 1950 FOREIGN PATENTS 487,763 Germany Dec. 18, 1929 

